Neurodegeneration, β-amyloid and mood disorders: state of the art and future perspectives

Objective Depression may increase the risk of developing Alzheimer's disease (AD). Recent studies have shown modifications in blood beta-amyloid (A) levels in depressed patients. This literature review examines the potential relationship between A-mediated neurotoxicity and pathophysiology of mood disorders. Design We conducted a review of the literature focusing on recent studies reporting alterations of plasma and serum A peptides levels in patients suffering from mood disorders. Results Different data suggest that patients with mood disorders are at great risk of developing cognitive impairment and dementia. In particular, low plasma levels of A42 peptide and a high A40/A42 ratio have been found in depressed patients. In addition, changes in A protein levels in patients with mood disorders have been associated with the severity of cognitive impairment and correlated positively with the number of episodes and severity of illness course. Conclusions Given the intriguing association between change in plasma level of A, depression and cognitive impairment, future work should focus on the relationship between A peripheral level(s), biomarkers of neurodegeneration and development of dementia in patients affected by mood disorders. Copyright (c) 2012 John Wiley & Sons, Ltd.